Apparatus and method for feeding flimsy sheets



July 7, 1970 R. A. TREMBLAY 3,519,265

APPARATUS AND METHOD FOR FEEDING FLIMSY SHEETS Filed Aug. 12. 1968 2 Sheets-Sheet l INVENTOR.

ROBERT A. TREMBLAY W *Bmm ATTORNEYS July 7, 1970 R. A. TREMBLAY APPARATUS AND METHOD FOR FEEDING FLIMSY SHEETS Filed Aug. 12, 1968 2 Sheets-Sheet 2 INVENTOR. ROBERT A. TREMBLAY ATTORNEYS United States Patent O 3,519,265 APPARATUS AND METHOD FOR FEEDING FLIMSY SHEETS Robert A. Tremblay, Hudson, NH, assignor to The International Paper Box Machine Company, Nashua, N.H., a corporation of New Hampshire Filed Aug. 12, 1968, Ser. No. 751,903 Int. Cl. B65h 3/30 U.S. Cl. 271- 9 Claims ABSTRACT OF THE DISCLOSURE An automatic end feed magazine presents a narrow strip of the exposed face of each succesive endmost sheet in a stack tangentially to a rotating suction feed roll, but with the strip spaced from the roll by a gate. A rotating friction element engages the exposed face to form a loop in the sheet While sliding the narrow strip out from behind the gate. The narrow strip may then be adhered to the roll to be slidably advanced off the stack.

BACKGROUND OF THE INVENTION In the sheet feeding art it is relatively easy to segregate the end sheet of a stack of sheets when the sheet material is stiff as in the case of box board blanks, or when the material is thick as in the case of folded flat boxes, folded newspapers, magazines and the like. It is also well known to segregate end sheets of relatively stiff, thick paperboard by means of a suction cup, moving in a straight or curved path, the material being sufficiently impervious to air to prevent the second sheet from being adhered and fed as a double.

However, with thin, flimsy, limp sheets such as letter paper, envelope stock, thin box board and the like, the conventional trailing edge feeds, suction cup feeds, and friction feeds all operate imperfectly because of the ad herence of one sheet to another, the tendency of the sheets to wrinkle and crumple, and the perforate nature of the sheets.

It has heretofore been proposed to feed flimsy sheets by rotating a combing wheel on the exposed face of the end sheet to loop, or buckle, the sheet out of its own plane and to then adhere a suction cup to the looped or buckled portion to feed the sheet, as disclosed in U.S. Pat. No. 1,715,358 to Han-old of June 4, 1929, and in U.S. Pat. No. 3,076,648 to Taylor of Feb. 5, 1963. In U.S. Pat. No. 1,460,336 to Hart of June 26, 1963, a friction foot is used to loop, or buckle, the endmost sheet and the sheet is then gripped by a suction cup at an unlooped portion resting flatwise on the next sheet so that doubling could occur.

SUMMARY OF THE INVENTION The device of this invention makes use of a friction element to loop or buckle the sheet but does not use the concept of suction adherence to the looped portion or the concept of suction adherence to an unlooped portion lying flatwise against the next successive sheet. Instead, in this invention, a suction roll, end feed magazine of the type disclosed in U.S. Pat. No. 3,148,876 to- Chandler of Sept. 15, 1964, is used. In that patent, the coated sheets are selfsupporting and the leading, or upper, edge of the endmost sheet is barred from advancing by abutting on the gate until suction bends the leading edge portion out of the plane of the sheet to a position opposite the sheet gateway. In this invention not only is the leading edge of the flimsy sheet barred from advancing, but a narrow strip of the exposed face is also barred from bending out of the plane of the sheet into engagement with the roll until it has been slid in the plane of the sheet by the friction looper, whereupon the strip can fall by gravity,

or be drawn by suction onto the roll for slidable segrega tion from the stack. The suction roll and the friction feed element rotate unidirectionally, in synchronization, so that the suction roll cannot adhere to the endmost sheet until the leading strip portion has been slidably released from behind the barrier and the strip is picked up by suction while the strip of the next successive sheet is firmly held behind the barrier awaiting the creation of a loop, or buckle, therein.

The principal object of the invention is to provide a positive feed for flimsy sheets in which only a single endmost sheet can be released from the magazine at one time, by frictionally buckling the sheet, in which suction is exerted on the sheet only in an area thereof separated from the next sheet by a barrier and in which the feeding of the sheet straightens out the loop, or buckle, to force air between the sheet and the face of the next sheet.

In the drawings:

FIG. 1 is a somewhat diagrammatic side elevation of the feed apparatus of the invention, showing the end sheet firmly held in the magazine.

FIG. 2 is a View similar to FIG. 1 showing the friction roll forming a loop in the end sheet while slidably releasing the upper edge portion from behind the barrier, or gate.

FIG. 3 is a view similar to FIGS. 1 and 2 showing the end sheet, after pick-up by the suction port of the suction roll and being advanced along a path away from the stack.

FIG. 4 is an enlarged diagrammatic side elevation of the barrier gate means of the invention, and

FIG. 5 is a perspective view from the stack end of the apparatus of the invention.

In the drawings, 30 represents the improved apparatus for feeding flimsy sheets of the invention, the major portion of the components thereof being similar to those shown in the above-mentioned U.S. Pat. No. 3,148,876, and incorporated by reference herein. The apparatus 30 includes a suitable frame 31, supporting an automatic end feed magazine 32, containing a stack 33 of fiat, planar, flimsy, limp sheets, such as the endmost sheet 34, the sheets being of thin paper, not self-supporting and pervious to suction by reason of their composition. Magazine 32 includes opposite side guides 35, an indexing bottom carrier 36 supporting the lower edge 37 of the sheets in the stack, a magazine outlet 38 and adjusting mechanism 39 for moving the outlet to a desired position.

The magazine 32 is fixedly positioned relative to the rotatably mounted suction roll, or drum, 42, to present each successive endmost sheet 34 arriving at the outlet 38 in substantially tangential relation to the smooth, cylindrical face 43 of the roll 42. It should be noted that the face 43 of roll 42 is not an end stop for the sheets in the magazine, but is positioned with its suction zone 44 about opposite the upper, or leading, edge portion 45 of the exposed face 46 of the endmost sheet 34 with the remainder of the exposed face 46 substantially spaced away from the roll. As clearly disclosed in U.S. Pat. No. 3,148,876, the suction roll 42 includes at least one suction port 47 on the face 43, the port 47 being connected by the conduit 48 in the rotating sleeve-type roll to register during rotation with the aperture 49 in the fixed hollow cylinder 50. Thus as the port 47 rotates unidirectionally in the direction of feed, suction is exerted therethrough in the zone 44 proximate the magazine to pick up a sheet, and suction is released at the end of zone 4 when the sheet is firmly held by, and under the positive control of, the belts 53 and 54.

As thus far described, the operation of the magazine 32 and suction roll 42 is identical with that disclosed in U.S. Pat. No. 3,148,876, with the exception that the suction roll does not contact the intermediate portion of the end sheet and is spaced from the same and located op- 3 posite the leading edge of the end sheet. The aperture 49,

conduit 48, and port 47 together with the unidircetional drive for the roll 42, indicated at 55, and the suction supply means 56 to the interior of the roll constitute the timed drive and suction supply and control means of the apparatus 30.

For convenience of description, the under face of each. end sheet 34 is designated 57, the next successive sheet is designated 58, the front face of the sheet 58 is designated 59, the faces 57 and 59 being subject to surface adhesion by reason of friction, and the second sheet tending to feed with the end sheet unless provision is made otherwise, especially with suction feed of flimsy paper.

As shown, in this invention a barrier, or gate, 62 is mounted on magazine 32 at the outlet 38 in the path of the upper edge portion 45 of the exposed face 46 of each successive endmost sheet 34. Barrier 62 may extend transversely across the full width of the magazine to bar the advance of a full width strip 45, if desired. However, it is preferred to provide a relatively narrow block 63, resting on the central portion of the upper, or leading, edges 45 of the sheets of the stack 33, and having the gate 62 as an integral down-turned flange, extending into the outlet 38 about one-half inch to one inch. The block 63 is supported by adjustment mechanism 65 on the cross rod 66 so that the gate 62 may be moved to conform to the height of the sheets. The inner face 61 of gate 62 is fiat and planar to restrain the end sheet, but the outer face 67 of gate 62 is beveled to form a tapered throat 68 with the surface 43 of roll 42, the throat 68 terminating in a sheet gateway, or passage 69, equal in width to the thickness of a single sheet 34.

It will be seen that the upper edge portion 45 of end sheet 34 cannot advace toward roll 42 unless it is slidably extracted from behind the barrier 62. The bottom carrier 36 serves as a barrier in the path of the lower, or trailing edge 37 of end sheet 34, preventing the edge 37 from slidable movement off the stack. Intermediate of the exposed face 46 of end sheet 34, and preferably proximate the lower edge portion, as shown, a rotatable, friction feed roll 72 is mounted on magazine 32 in rear of the outlet 38.

The friction feed roll 72 is provided with a smooth substantially frictionless cylindrical surface 73, having a friction element 74 inserted therein and protruding therefrom so that with each revolution of the roll the friction element 74 engages the exposed face 46. Roll 72 rotates unidirectionally in timed synchronization with suction roll 42 by means of the power train 75 (FIG. 3), so that a loop, or buckle, 76 is formed in end sheet 34 just before the suction port 47 of roll 42 reaches the suction zone 44. As the loop 76 is formed the upper edge portion, or strip, 45 of the end sheet 34 is slidably released from the restraint of the face 61 of gate 62, the limp fiimsy nature of the sheet permitting the upper portion of the end sheet to fall by gravity and/or be drawn by suction of port 47 into a rapid firm adherence on the face 43 of the suction roll 42. Thereupon the continued rotation of suction roll 42 slidably extracts the end sheet 34 from the magazine, at the same time tensioning and tautening the sheet to eliminate the loop 76. As the loop is rapidly flattened out, the air captured therein is forcibly driven into the space between the under face 57 and front face 59 to form an air cushion which avoids any tendency toward double feed.

The smooth cylindrical face 73 of friction roll 72 serves as an end stop for the end sheets 34 with no tendency to impart motion to the sheet. Additional relatively friction free rollers 80, may also be used as magazine end stops to avoid any tendency of the stack to bulge.

The protruding friction element 74 jogs the stack with each revolution, thus adding a jogging function for separating the end sheet to its principal function of creating a loop or buckle.

The adjustment mechanism 65 for the gate 62 not only positions the block 63 in the desired location, but also permits adjustment of the width of gateway 69 to conform to the thickness of the sheets in the stack.

The friction feed roll 72 is preferably located as near the bottom of the exposed face 46 as pracitcal in order to perform its air separation function over substantially the full height of the sheets. The friction element 74 preferably extends continuously across the full width of the face 34 of the sheets in order to apply uniform friction and thereby avoid wrinkling or crumpling of the sheets.

What is claimed is:

1. Apparatus for individually and successively feeding single, flimsy, limp sheets from a stack of said sheets, said apparatus comprising:

a rotatable cylindrical suction roll having a smooth cylindrical face with a suction port therein, said port being operable in a predetermined suction zone of rotation of said roll;

an automatic, end-feed sheet magazine presenting each successive endmost sheet in said stack to the magazine outlet with one face exposed, one edge barred from sliding movement outwardly of said stack, and the opposite edge proximate the said suction zone of said roll;

a barrier on said magazine means, at said outlet, said barrier having an inner face in the path, of the portion of said exposed face extending along said opposite edge to bar the advance thereof and having an outer face at a spaced distance from the smooth face of said roll to form a single sheet passage, or gateway, therebetween;

a rotatable friction feed roll on said apparatus, mounted to periodically frictionally engage the exposed face of each said endmost sheet and slide the same toward said one edge to loop the same away from the next successive sheet While sliding the opposite edge portion thereof from behind said barrier to release said edge portion;

suction supply and control means operably connected to said suction roll to apply suction to said port, in said zone, for adhering to said released edge portion;

and timed means for rotating said suction roll and said friction roll in synchronization to cause said suction roll to slide each successive sheet, released from behind said barrier, through said gateway and away from said magazine means.

2. End feed magazine apparatus for feeding limp, flimsy sheets individually and successive from a stack of said sheets, said apparatus being of the type having a rotating suction feed roll substantially in tangential contact with the upper edge portion of the exposed face of the endmost sheet of said stack, and having a sheet magazine urging said stack in the direction of said roll, said suction roll being positioned to adhere to said upper edge portion of each successive endmost sheet and slidably advance said sheet along a path away from said stack, said magazine apparatus being characterized by:

gate means on said magazine, mounted in the path of the said upper edge portion of each endmost sheet and barring the advance thereof, said gate means being spaced from said roll and forming a single sheet gateway therewith;

a support on said magazine, mounted in the path of the lower edge of each endmost sheet and barring the downward sliding advance thereof; and

rotating friction feed means on said apparatus, synchronized with said rotating suction roll, said means periodically frictionally engaging the intermediate portion of the exposed face of each endmost sheet and creating a loop therein, while slidably releasing the said upper edge portion from behind said gate for adherence by said suction roll and slidable advance through said gateway and away from said stack.

3. End feed magazine apparatus as specified in claim 2, wherein said gate means comprises a block mounted to rest on the upper edges of the sheets in said stack and having an integral downturned flange thereon, said flange having a fiat inner face engaged by the upper edge portion of each endmost sheet in said stack and having a beveled outer face forming a tapered throat with the curved surface of said suction roll, said throat constituting said gateway.

4. End feed magazine apparatus as specified in claim 3, wherein said gate means includes mechanism for adjusting the position of said block and flange to increase and decrease the width of said gateway.

5. End feed magazine apparatus as specified in claim 2, wherein said rotating friction feed means is a smooth-faced roll having a friction element thereon projecting a substantial distance from said smooth face to jog said stack, when frictionally looping each sheet and then permit said loop to be removed by the feed action of said suction roll,

whereby the air in said looped portion is forced into the space between said endmost sheet and the next successive sheet to prevent double feeding.

6. End feed magazine apparatus as specified in claim 2, wherein said roating friction feed means is mounted on said apparatus proximate the lower edge portion of the exposed face of the endmost sheet in said stack, whereby the loop created in said endmost sheet by said means, when eliminated by the suction advance of said sheet by said suction roll, forces air between said endmost sheet and the neXt successive sheet in said stack substantially over the entire area of said sheets.

7. End feed magazine apparatus as specified in claim 2, wherein said rotating friction feed means includes a smooth-faced roll having a friction element thereon, said element extending transversely continuously for the full width of the exposed face of each endmost sheet in said stack for avoiding wrinkling of said limp, flimsy sheets.

8. End feed magazine apparatus as specified in claim 2, wherein said rotating friction feed means is mounted proximate the lower edge portion of the exposed face of said endmost sheet, and

said magazine includes an end support, in substantially friction-free engagement with the central portion of said exposed face to prevent bulging of said stack and to prevent collapse of an end sheet released from behind said gate.

9. The method of feeding limp, flimsy sheets, individually and successively, from the end of a stack of said sheets, by means of an end feed magazine and a suction feed roll, said method comprising the steps of:

presenting each successive endmost sheet in said stack to the face of said roll tangentially, with one edge portion of the exposed face thereof proximate said roll;

barring the slidable movement off said stack of the opposite edge of said endmost sheet; barring the advance of a narrow strip of the said one edge portion toward the face of said roll; and

frictionally engaging the exposed face of each endmost sheet and sliding said sheet into looped configuration to release the said narrow strip of said one edge of said sheet and permit said strip to be adhered on said suction roll.

References Cited UNITED STATES PATENTS 2,569,692 10/1951 Rockwell.

EDWARD A. SROKA, Primary Examiner US. Cl. X.R. 271-22 

